Apparatus comprising diaphragms



Nov. 17, 1964 ROHACS 3,157,763

APPARATUSES COMPRISING DIAPHRAGMS Filed Feb. 27, 1962 INVENTOR ATTORNEYUnited States Patent This invention relates to apparatuses comprisingmembranes or diaphragms, in which the deformation of the membrane underthe action or" a pressure is utilized either to measure the variationsin pressure or to act as a function of these variations on a controlledmember.

This deformation which is a function of the diameter, the nature of themetal and its thickness is, in consequence, restricted within verynarrow limits, which causes restrictions in use, both as concerns therange, that is to say the interval between the limits between which thevariations are used, and as concerns the working pressure, that is tosay either the means value between the limits or the value of each ofthese limits.

According to a first improvement, a double-walled diaphragm is used asalready known, but the shells, constituting the walls of the pressurechamber, are mounted to allow both shells free to respond to changes inpressure inside the pressure chamber.

According to a second improvement, the deformation is transmittedthrough an elastic member, the elasticity of which can be modified inthe position of use, more particularly by a remote control.

One embodiment of the inventive idea will be given hereunder without itsbeing intended to restrict the generic scope of the invention to thefeatures given in the ex ample selected for illustration.

In the accompanying drawings the invention has been shown as applied tothe control of a contactor.

FIGURE 1 is a diagrammatic section through an apparatus according to theinvention, and

FIGURE 2 is a section along the line 2-2 of FIG- URE 1.

In the figures, 1 designates generally a casing which contains acontactor 2 as well as a diaphragm detector and its adjusting member.

The contactor is of any usual commercial type and therefore its designand functioning will not be described, It is controlled by a movablecontactor part or push button 3.

It is for the control of this push button that the diaphragm detector,which is constituted as follows, is used:

In the upper part of the casing, designated more particularly by 4 andclosed by a cap 5, is located the double diaphragm designated generallyby 6 and constituted by two thin shells of steel, namely the lower shell7 and upper shell 8; each of these shells has a peripheral flange so asto leave therebctween even in the position of rest, a space 9.

The upper shell has an extension 10 provided with a central bore 11which opens into a connection 12 by means of which the source ofpressure is connected.

The edges of the shells 7 and 8 are pressed firstly between a shoulderon a sleeve 13 and secondly between a nut 14 which is screwed by meansof an internal thread into the sleeve 13. Between the two shells islocated a packing 35 of rubber or similar material having a circularcross-section 35.

The sleeve 13 moves freely in the casing 4, in which it is simplysupported by the extension 10, which is locked in a housing ofcorresponding form in the cap 5. The position of the lower shell 7 ismarked by a push-rod 15 which passes by means of a sleeve through a wall16, which forms the lower part of the casing 4.

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It follows from the foregoing that under the eifect of the pressure, theshells 7 and 8 constituting the double shell may assume a lenticularform, each diaphragm having a semi-lenticular form. The result of thisis that the displacement is double what can be obtained, all otherthings being equal, with a single shell.

Instead of permitting the push rod 15 to bear directly on the pushbutton 3, there is interposed between the push button and the push rod,a stirrup-member 17, at the base of which is inserted a rigid metalpacking 38.

The stirrup member 17 is supported by a second stirrup member 18, theplane of the branches of which is perpendicular to the plane of thebranches of the stirrup member 17, as seen in FIGURE 2.

The stirrup member 18 is held by journals 19 and 20 which may moveinside two apertures 21 and 22 formed in the casing 1.

These journals are integral with sleeve 23 having an internal thread andthrough which passes threaded rod 24, which is terminated by head 25,which passes through the wall of the casing 1 and this head is held soas to prevent any longitudinal movement by plate 26 housed in thethickness of the wall of the casing.

The head 25 is provided on the outside with a slot, which enables thehead to be turned by means of a screw driver, thus allowing the stirrupmember 17 to be displaced with respect to the push rod 15.

As a result, if the stirrup member 17 is withdrawn to the extreme right,the push button 3 and the push rod 15 will bear on the flexible ends ofthe branches of the stirrup member and there will therefore be aconsiderable dead stroke before the action of the push rod 15 istransmitted to the push button 3. If on the other hand, the stirrupmember 17 is pushed to the left, so that the push button 3 and the pushrod 15 bear on the part of the branches enclosing the packing 38, thetransmission of the action of the push rod 15 on the push button 3 willbe instantaneous.

The action of the stirrup member 17 may be combined with anotherregulating device for allowing the push button 3 to be moved away fromthe stirrup member 17 to a greater or lesser extent.

To this end, the contactor 2, instead of resting on the bottom of thecasing, is housed in a cradle 27, which is fixed to the body of the case1 at two points 28 and 29 by riveting or by any other means. These twopoints determine an axis of rotation.

At the other end of the cradle 27, the latter bears on a nut 39, whichis controlled by a screw 30, the head 31 of which is accessible from theoutside. The head is immobilized inside the casing by plate 32.

One may therefore, either by acting on the head 25 or on the head 31, orby acting on both these heads, vary firstly the range of operation andsecondly the working pressure.

What I claim is:

1. In a pressure responsive switch of the type including a movablecontactor adapted to be moved to complete a circuit, a pressure chambercomprising a pair of shells each provided with a transversely extendingperipheral flange extending toward the other with their free edges inmutual contact to thereby define a pressure chamber whereby both shellsare free to respond to changes in pressure within the chamber, means forclamping the shells together comprising a pair of rings respectivelyabutting the outer surfaces of the shells about their marginal edges andhaving cooperating means for detachably securing them together totightly clamp the flange edges against each other, a support, means atthe center of one of the shells for freely suspending them and theattached clamping means from the support in fixed relation thereto,conduit means in said support whereby the inside of ber extending alongthe internal surfaces of the flanges,

whereby the packing is pressed towards said flanges in response tointernal pressure within the chamber for sealing the shells along theline of mutual contact of the flanges.

3. In a pressure responsive switch as defined by claim 1 in which theclamping rings are provided with respective internal and external screwthreads for detachably securing them together.

4. In a pressure responsive switch as defined by claim 1 in which themeans for transmitting the movements of the other shell comprises anelongated flexible member extending transversely between the other shelland said nrovable contactor, means movably supporting the flexiblemember at one end thereof for transverse movement relative to thedirection of displacement of said contactor, and means for shifting thesupport and flexible member longitudinally thereof.

5. In a pressure responsive switch as defined by claim 4, in which theflexible member is provided by a pair of flexible arms branching attheir ends from the support means and extending in transversely spacedparallel relation, and a rigid packing between the arms adjacent to thesupport.

7 References Cited in the file of this patent UNITED STATES PATENTS1,741,120 Tandberg Dec. 24, 1929 2,109,145 Farmer Feb. 22, 19382,129,986 Berghoefer Sept. 13, 1938 2,284,588 Rineer May 26, 19422,376,475 Bush May 22, 1945 2,394,401 Overbeke Feb. 5, 1946 2,523,213Hilgert Sept. 19, 1950 2,565,472 Castel et a1 Aug. 28, 1951 2,656,428Harris Oct. 20, 1953 2,839,630 Wood .a June 17, 1958. 2,914,743 NunnNov. 24, 1959 FOREIGN PATENTS I 839,586 Germany May 23, 1952 374,464Great Britain June 7, 1932

1. IN A PRESSURE RESPONSIVE SWITCH OF THE TYPE INCLUDING A MOVABLECONTACTOR ADAPTED TO BE MOVED TO COMPLETE A CIRCUIT, A PRESSURE CHAMBERCOMPRISING A PAIR OF SHELLS EACH PROVIDED WITH A TRANSVERSELY EXTENDINGPERIPHERAL FLANGE EXTENDING TOWARD THE OTHER WITH THEIR FREE EDGES INMUTUAL CONTACT TO THEREBY DEFINE A PRESSURE CHAMBER WHEREBY BOTH SHELLSARE FREE TO RESPOND TO CHANGES IN PRESSURE WITHIN THE CHAMBER, MEANS FORCLAMPING THE SHELLS TOGETHER COMPRISING A PAIR OF RINGS RESPECTIVELYABUTTING THE OUTER SURFACES OF THE SHELLS ABOUT THEIR MARGINAL EDGES ANDHAVING COOPERATING MEANS FOR DETACHABLY SECURING THEM TOGETHER TOTIGHTLY CLAMP THE FLANGE EDGES AGAINST EACH OTHER, A SUPPORT, MEANS ATTHE CENTER OF ONE OF THE SHELLS FOR FREELY SUSPENDING THEM AND THEATTACHED CLAMPING MEANS FROM THE SUPPORT IN FIXED RELATION THERETO,CONDUIT MEANS IN SAID SUPPORT WHEREBY THE INSIDE OF SAID PRESSURECHAMBER MAY BE CONNECTED TO A PRESSURE SOURCE, AND MEANS OPERATED BY THEOTHER OF THE SHELLS FOR TRANSMITTING MOVEMENTS THEREOF IN RESPONSE TOCHANGES OF PRESSURE IN THE CHAMBER TO SAID CONTACTOR.